Tom Hayes – the bank trader known to colleagues as Rain Man, who authorities allege was the key figure of a global interest-rate-rigging scheme, was working at UBS in Tokyo back in 2008. He had developed a reputation as an aggressive, lucrative derivatives trader.

It turns out, though, that Goldman’s attempt to hire Mr. Hayes was much more serious. The firm formally offered him a job as managing director, according to a Goldman spokesperson. Goldman also dangled a $3 million guaranteed payout for 2008, according to people familiar with the offer.

(To be clear, there is no reason to suspect that Goldman had any inkling at the time that Mr. Hayes was allegedly engaged in what U.S. and British authorities now describe as illegal activity. And while Mr. Hayes is today well known for his alleged role in the Libor scandal, former colleagues say he was making lots of money through other types of trading.)

UBS battled, successfully, to retain its star trader, who ended up generating more than $250 million in trading revenue during his roughly three years at UBS in Tokyo. “One of my most talented young traders in Tokyo, Tom Hayes, is being aggressively pursued by Goldman Sachs,” a UBS investment-banking executive in London wrote in a June 2008 email to his colleague that was reviewed by the Journal. UBS executives decided to give him extra responsibilities and a bigger pay package, according to people familiar with the matter and internal UBS emails.

Notwithstanding the retention campaign, Mr. Hayes joined Citigroup in late 2009. The New York-based bank quickly came to regret the hire, firing Mr. Hayes less than a year after he arrived for what it described as misconduct – allegations that Mr. Hayes refuted at the time.

Mr. Hayes has been charged with fraud-related crimes in the U.S. and U.K. He hasn’t entered a plea to either country’s charges. He wrote in a January text message to the Journal that “this goes much much higher than me.”